If You are Considering Lightroom
How would relocate masters and import them (in LR) be any different the export originals and include IPTC information?
Lightroom doesn't read XMP files that belong to JPEG or TIFF files, so exporting originals with XMP files doesn't work for non raw-files. I forgot that you can also write the IPTC into the exported files. That would indeed not be much different, except that you need enough disk space to have two copies of each image.